best selling books lists are known to be farcical circle jerks. Especially political nonfiction. You do a bunch of book tours with ghouls and a bunch of think tanks buy copies to artificially inflate the sales numbers, only to resell them or give them away at events, then pundit media gives you an extra boost for regular retail sales. I mean maybe some people are organically buying hillbilly elegy, but I wouldn't have ever heard of it if it weren't for the socdem podcasts like chapo cringing at it on air (which is its own form of free attention).